[Homocysteine-related genes and attention in patients with schizophrenia and schizoaffective psychosis].

The elevated level of homocysteine has been repeatedly observed in patients with schizophrenia. Molecular-genetic studies revealed the association between schizophrenia and polymorphisms of two genes - methylenetetrahydrofolate reductase (MTHFR) and cystathionine-beta-synthase (CBS) involved in the conversion of homocysteine to methionine and cysteine, respectively. Authors have studied the association of C677T MTHFR and 844ins68 CBS polymorphisms with attention in 105 schizophrenic patients (56 women and 49 men) by measuring auditory evoked potentials and concentration of attention. Women with a genotype containing an insertion (Ins+) had the shorter latency of N100 in the frontal leads compared to those with the Ins- genotype. The results of the neuropsychological study revealed that women with Ins+ genotypes performed better on the test as well. In conclusion, the 844ins68 CBS polymorphism is associated with attention in patients with schizophrenia.